What is the reason for sealing your fermenter (air tight)

I know that it is for keeping germs and what not out of the brew but is their more? And something off topic here; Does anyone know what a unhopped beer is call? I have heard malt liquor but i dont know.

thanks
Dan

Keeping the bad stuff out and preventing evaporation. I have no idea on the malt liquor think. Try to stay away from the Colt 45.

Jason

haha thanks for the reply Jason.

Since air is moving all the time if you open ferment you're going to introduce oxygen to the beer. I have no idea how much or what difference it will make in the final product, but that's one of the main reasons.

n/m about malta, my brain was malfunctioning.

fishermand715 said:

I know that it is for keeping germs and what not out of the brew but is their more?

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Pressure, believe it or not is good for beer up to 15 psi. There are brewers that actually pressure ferment. This is yet another favorable reason to use a blow off tube instead of an airlock (more back pressure), but you need a good seal.

There are also brewers that do "open fermentation" so it is not all that critical. What is critical is the environment the beer is brewed in. I would recommend trying to get a decent seal if possible.

As for malt liquor... hopless beer you say? I will guess it is made by BMC...

Seriously? The delta between an air lock and blow off is negligible.

Jason

There is not more to it. You could simply place the lid on top and due to the fermentation giving off CO2(which is heavier than air) it'll create a safety blanket on top of your beer. Some beers are fermented this way and I believe this is the traditional way English beers are made.

I know SN Bigfoot is fermented open but they can do it in a controlled room to help keep it clean. If you have a clean area that you can keep your fermenters then there is no harm in keeping them open.

The so-called CO2 blanket is part of it, but there is also the positive pressure of fermentation....gas is constantly flowing from out of the fermenter, which keeps airborne beer-spoiling bacteria from being pulled in.

To answer the OP question, a tight fitting fermenter lid really isn't required; I think it makes people feel better more than anything.

JasonInBTR said:

Seriously? The delta between an air lock and blow off is negligible.

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huh? I have and now do leave the blow off tube on for all of fermentation. The end result is more CO2 in solution. The beer actually comes out with a slight "fizz" in it...at least in the hydro sample anyways!

I do not think there is a huge difference just a slight one. I am convinced that the difference between good beer and GREAT beer are hundreds of these subtle differences that all add up into the end product.

To each their own! That is the coolest part about this stuff......everyone comes up with their own little things.

Jason

For the unhopped beer, I've run across gruit. Before hops were the thing people would use various herbs for their bittering.

Un-hopped beer is still beer, just really sweet. Gruit is the herbs/spices etc. used to bitter beer before hops came along to take the edge off of the sweetness. There have been different definitions of "beer" over the ages and various regions (i.e. reinheitsgebot) though.

thank you all for replying back. This forum has been very helpful.

Dan

You want it sealed so that oxygen can't get in. Just because CO2 is being created inside and forcing its way out doesn't mean O2 won't come in, especially after active fermentation has slowed. This is especially true if you give the primary time to clear.

Bobby_M said:

This is especially true if you give the primary time to clear.

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But what about the CO2 blanket?






(another myth that won't die)

If you are careful about not introducing oxygen in the wort post fermentation, I very much doubt you'll ever run into problems with oxidation unless you plan on aging the beer for several months. I pretty much only open ferment (bucket lid cracked open for active fermentation), but I try to bottle earlyish (2-3 weeks), using gelatin/cold crashing to clear if needed as to reduce contact time with air. Using a true top cropper will also help shelter the beer from air.

For bigger beers than what I'm usually brewing (in 10 batches, only one was 1.050+), I'll throw an airlock on a carboy and bulk age.